[Mpower]

Originally Posted by adya33

With introduction of MPFI Opel Astra went from 75BHP to 92BHP.
Though previously it was single point fuel injection and not carb.

You are right adya33, they are both 8 valve and its a big jump. However was it not an all new engine that showed up in the newer Astras? The old one was 16NZR or something and I dont recall the name of the new engine.

[sajo]

Originally Posted by Mpower

So far, Conti, Indica got only EFI with no power gain.

The Carb Indica made 60Bhp. The FI Indica2000 (the first of this generation) made 75Bhp. So it did get a power boost.

[Ford Rocam]

To explain in laymen terms Fuel injection can control better air/fuel ratio in an engine with varying load conditions by using different sensors (like oxygen sensor in exhaust) & giving feedback to the ECM which inturn controls or regulate fuel supply to the injectors to get optimum combustion thereby giving better economy & power a thing carb would not able to do that effectively.
Some one correct me if i am wrong.

[Mpower]

Originally Posted by sajo

The Carb Indica made 60Bhp. The FI Indica2000 (the first of this generation) made 75Bhp. So it did get a power boost.

Oops....are those Nikes in my mouth !!!

Neeways, I can attribute this to another feature...which is the 'tuned intake manifold'. Having a single carb or TBI means the intake runners are unequal length and there is no plenum. Using MPFI with equal length runners and a plenum will also give you more tuning effect (volumetric efficiency) and hence horsepower. Optra 1.6 takes this concept to the next level with VGIS.

[rdkarthik]

The overall peak power with the same engine engine hardware is almost the same in a carb or fuel injected system... Big advantage i have seen, when working on programmable ecus, is the ease of setup..... Compare chaging jets on different circuits on a carb ( imagine if its a 4 carb race setup ) to punching numbers on the laptop .. You can do things a LOT quicker and a LOT more accurately.
Then you also have the major benefit of reduced emissions. So anyday for me its fuel injection!!!!

[veyron1]

Originally Posted by nitroxx

Veyron 1 .... Bugatti 1000 bhp ....Carbs? If knowledge is a treasure chest then the mind is the key to open.

@nitroxx: i'm not sure what you're getting at? i've never favoured a carb setup, or implied so in my post- let alone dragging in the floundering fantasy of a carb'd veyron..??! mind explaining what's going on in that mind of yours??

[heavy_foot]

Originally Posted by Ford Rocam

To explain in laymen terms Fuel injection can control better air/fuel ratio in an engine with varying load conditions by using different sensors (like oxygen sensor in exhaust) & giving feedback to the ECM which inturn controls or regulate fuel supply to the injectors to get optimum combustion thereby giving better economy & power a thing carb would not able to do that effectively.
Some one correct me if i am wrong.

hey nice explanation ...also almost all of the fuel injected engines have a engine management system which controls the ignition timing more effectively which in turn results in more power.

[sumitkalindi]

Originally Posted by nitinbhag

I would have said fuel injection is much better till around a month ago..

However, after my Siena has spent 4+ weeks in the garage (Sundaram & Bosch) and no solution other 'change ECU' in sight yet (and no spare ECU available), I am wishing that it was a carburated engine

Nitin, I am forced to say that this is more due to Fiat's internal problem that the complications of FI engines. Yes modern technology has its cost, but look at the end results. This is much better. Rememeber the days when Good ol Amby Or Premier were the only mooving thing on the Roads?

I still remember, My dad owns a Premier, I would drive it in the city, Bulldozing my way through Calcutta's Auto's, little fearing what a dash would result in. Everything was soo cheap. And I really loved our trip to the local Garage, twice each month, just to keep everything in shape.

I now own A Indica V2 Deisel, use it extensively in the north east, with out any fear of it breaking down in middle of nowhere. Yep the regular visit to the Authorised Service Center costs more, than each visit to the local garage. But it is less frequent and Overall comes with peace of mind. I know I don't have to get my hands dirty, though I loved to get that extra admiration from my GF when ever our Fiat started to choke and cough and I the Kam Chalau mecahnic could fix er up.

[Rehaan]

Originally Posted by rdkarthik

The overall peak power with the same engine engine hardware is almost the same in a carb or fuel injected system...

Fuel Injection all the way. I hate carbs as i have had the worst luck with them!


Rdkarthik, has a good point. Carbs CAN be tuned to put out just about the same power as a FI setup on the same engine and for set conditions.

FI however has the advantage of being able to tune the mix appropriately throughout the RPM range and not just at peak power / set RPM, not to mention being able to cope with changes in conditions with ease.

Originally Posted by Ford Rocam

To explain in laymen terms Fuel injection can control better air/fuel ratio in an engine with varying load conditions by using different sensors (like oxygen sensor in exhaust) & giving feedback to the ECM which inturn controls or regulate fuel supply to the injectors to get optimum combustion thereby giving better economy & power a thing carb would not able to do that effectively.
Some one correct me if i am wrong.

Absolutely! Had drawn some MSpaint diagrams in a thread long ago to explain exactly what you managed to say in one paragraph. One of my favourite thread titles @ TBHP - Do MPFI cars have Carbs?

cya
R

[viper]

Hi,

For the man who does not have deep pockets it would be carbs. They are repairable and can b emodified/tuned/altered/swapped to get your required performance/economy at affordable prices. Most racers would prefer carbs as not many are versed with the electronics. They can acheive similar or better results than the MPFI equivalent cars which are chipped/remapped given the same budgets involved(eg zens, esteems with different carbs only not engines).

I have voted for Fuel Injected as it is no longer easy to access good conditioned Carb cars. If I wanted a drag car it would be a esteem with a swapped engine(baleno/1.3lDOHC) running carbs anyday. Much chepaer to kill say a Vtech or OHC 1.5 and easier to maintain.

Viper

[Fiero]

the main reason the switch from carb to mpfi came was that mpfi are potentially much cleaner

with the current emmision norms ... i don't think a carb can generate as much power as the mpfi ... and not to mention .... you gotta keep the emissions in regular check in a carb ... mpfi is troublefree on that front

you might wonder that a typical 1.6L in the mid 80's produced 120+ bhp ... which car mpfi does that now ??? but thats mainly due to the difference in emission norms back then ... and now

[DRC]

My vote for the FI ..
I have to agree with every one's voices here, seems all are right!!
Actually, ECUs provide more flexibility than carbs for tuning, and you dont have to change any mechanicals either, but for the manufacturers hide info to benifit their cash box. in today's world all electronics used for the ECU and army of sensors are dirt cheap. Only with the connectors specific to a perticular car, and a some bias, some unshared information make them prohibitively expensive,

You will get a generic pressure sensor for a few 10s or 100s of rupees ( try it in SP road bangalore), but with that stupid connector for your car, it may cost you 15K , when bought in auth dealership.

There are lot of such things associated with a car. The guys who service your car are not engineers, if there are engineers they are usually mech are auto engs, for them any electric/ electronics part is an other part which they do not want to take a chance, and manufacturers make money threatening you to void the warranty, and even out of warranty, of tampering and hence need to replace the whole system even if not necessary...

Life sucks..right

[speedsatya]

i go for MPFI ...as you can feel the differnce when drive same cars with carb and mpfi ...
but mpfi means better fuel as adultrated fuel can clog teh injectors ...carb's can be serviced easily and FI's need expert care...
also in case of mpfi's the fuel pump needs battery power whereas in carbs it doesnt ...

[Steeroid]

Originally Posted by viper

For the man who does not have deep pockets it would be carbs.

You've got the drift, viper. I dont think I have questioned the benefits of FI - what was intended was a cost-benefit analysis, and most of you will agree that the costs associated with an FI engine are much higher than that with a carb-based engine.

Science is always taking us towards newer boundaries. However, it is important to bear in mind the suitability of technology as well as the effectiveness of the same versus the costs involved.

Today we have cars that wont start up without electrical power. I have one that wont even UNLOCK itself if the battery is down - I have to open the tiny hatch and crawl in through the back because they've done away with mechanical locking systems entirely.

I also feel that there are other reasons for manufacturers to push FI - dont we now HAVE TO go to the 'Authorized Service Centres' because they are the only ones who can decode the ECU software? Or are capable of checking the army of sensors? If you had a carb-ed vehicle, you would still have the option of cheaper service - it is then upto you to use that option or dismiss it.

FI by itself would have been fine, but the whole concept of FI has been used to turn the car into something that can only be touched by the manufacturer. And when repairs are required, as in Nitin's case, they are usually very expensive.

Again, in the case of extreme circumstances like the Mumbai floods, wouldnt a carb-ed vehicle have been back on the roads much faster than its electronic cousins that had to wait for ECUs and had their warranties nullified? I also have a 32-bit ECU equipped vehicle that needs to be switched off and turned on again once I reach higher altitudes because the ECU needs to reset itself - else I loose boost on the fuel injection commonn rail.

My point is that the whole FI exercise has resulted in a technology overkill in cars. Was FI the cause, or was it merely the excuse?

[directinjection]

Originally Posted by Mpower

RT, the power hike was due to the switch from 8 valves to 16 valves.(all Marutis) So far, Conti, Indica got only EFI with no power gain.

When Indica was launched, its petrol version came fitted with a carburettor and developed (if I remember correctly) 60 or so BHP. When Indica 2000 was launched in 2000 with an MPFI version of the same engine, the power went up to 75 and then again to 85 in the Indigo/Cityrover version. The increase in power was obtained while still retaining the two-valves-per-cylinder configuration. So, it is probably wrong to attribute Esteem's power hike only to the four-valve set up.